There are significant costs and logistical problems related to the provision of so-called heavy duty wiring harnesses that utilize Deutsch connectors for aftermarket installations of vehicular data bus accessing devices, including for example telematics devices for variously recording and/or transmitting vehicular data. Although the cylindrical form factor associated with such connectors is reasonably standard in the industry, the problems arise in providing for compatible flanges in mounting the connectors on differing manufacturers' vehicles, where the flange provisions for chassis OEM mountings of the in-cab diagnostic link connector can differ.